suspend/resume kernel panic, Intel HD Graphics 5500, UEFI with CSM, HP dock, DisplayPort DP-1 or DP-2

[grahamperrin]

HP EliteBook 850 G2 notebook, docked, with a Philips display.

2017-03-13 20:22 in irc://irc.efnet.org/#freebsd-xorg

… with CSM, waking from sleep, probably in a dock: https://goo.gl/photos/jUdJPnGwNGg3zZc18

– photograph taken by me Wednesday 2017-03-08 09:26

This morning in irc://chat.freenode.net/#freebsd

… tempted to say that it's i915 related.

I'll reproduce the panic some time after I get to work, then add some hardware and software details.

[hselasky]

Hi,

It looks like some DRM code is using blocking calls when not allowed to use blocking calls. Maybe the resume sequence needs to be run from a taskqueue.

--HPS

[grahamperrin]

Thanks. Incidentally –

I'll reproduce the panic

– I have not yet reproduced the panic :-/

As far as I recall the steps were not exotic but this is (or was) the type of bug where I find it difficult to get reproducible steps if I think too hard about it. If that makes sense :-)